Medical device

ABSTRACT

A medical device including a shaft having an elongated inner member and an elongated tubular reinforcing member disposed over at least a portion of the inner member. In some embodiments, at least a portion of the outer surface of the inner member is spaced from the inner surface of the reinforcing member, defining a space substantially free of any other structures of the device. In some embodiments, the shaft can include a tip structure disposed on a distal portion of the inner member. In some such embodiments, the reinforcing member has a distal end, and the tip structure is disposed on the distal portion of the inner member adjacent the distal end of the reinforcing member. Additionally, in some embodiments, the reinforcing member can include a plurality of apertures defined therein, for example, to enhance the flexibility or other such characteristics of all or portions of the reinforcing member.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/477,755, filed May 22, 2012, now U.S. Pat. No. 8,636,716; which is acontinuation of U.S. application Ser. No. 12/470,261, filed May 21,2009, now U.S. Pat. No. 8,182,465; which is a continuation of U.S.application Ser. No. 11/180,187, filed Jul. 13, 2005, now U.S. Pat. No.7,540,865; which is a continuation of U.S. application Ser. No.10/400,750, filed Mar. 27, 2003, now U.S. Pat. No. 7,001,369, thedisclosures of which are incorporated herein by reference.

This application is also related to U.S. application Ser. No.11/505,119, filed Aug. 16, 2006, now U.S. Pat. No. 8,048,060, thedisclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates generally to medical devices. More specifically,the invention relates to a medical device, such as a catheter or thelike, including an elongated shaft having a reinforcing member disposedabout a portion of the shaft.

BACKGROUND

A wide variety of medical devices have been developed for intracorporaluse. Elongated medical devices are commonly used to facilitatenavigation through and/or treatment within the anatomy of a patient. Avariety of elongate medical devices such as catheters, endoscopes andthe like have been developed over the past several decades. Because theanatomy of a patient may be very tortuous, it is desirable to combine anumber of performance features in such devices. For example, it issometimes desirable that the device have a relatively high level ofpushability and torqueability, particularly near its proximal end. It isalso sometimes desirable that a device be relatively flexible,particularly near its distal end. A number of different elongatedmedical device structures and assemblies are known, each having certainadvantages and disadvantages. However, there is an ongoing need toprovide alternative elongated medical device structures and assemblies.

SUMMARY OF SOME EMBODIMENTS

The invention provides design, material, and manufacturing methodalternatives for medical devices. In some embodiments, the medicaldevices can include a shaft having an elongated inner tubular member andan elongated tubular reinforcing member disposed over a portion of theinner tubular member. In some embodiments, the reinforcing member isdisposed about a proximal portion of the inner tubular member such thata distal portion of the inner tubular member is free of the reinforcingmember. In some embodiments, at least a portion of an outer surface ofthe inner tubular member is spaced from an inner surface of thereinforcing member. In some embodiments, the shaft can include a tipstructure disposed on the distal portion of the inner tubular member. Insome such embodiments, reinforcing member has a distal end, and the tipstructure is disposed on the distal portion of the inner tubular memberadjacent the distal end of the reinforcing member. Additionally, in someembodiments, the reinforcing member can include a plurality of aperturesdefined therein, for example, to enhance the flexibility or other suchcharacteristics of all or portions of the reinforcing member.

The above summary of some embodiments is not intended to describe eachdisclosed embodiment or every implementation of the present invention.The Figures, and Detailed Description which follow more particularlyexemplify these embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of thefollowing detailed description of various embodiments of the inventionin connection with the accompanying drawings, in which:

FIG. 1 is a partial side plan view of a medical device in accordancewith one example embodiment of the invention, shown as a guide ordiagnostic catheter;

FIG. 2 a partial cross sectional view of a portion of the medical deviceof FIG. 1;

FIG. 3 is a partial cross sectional view of a portion of the medicaldevice of FIG. 1, taken along line 3-3 of FIG. 1;

FIG. 4 is a partial cross sectional view similar to the view of FIG. 3,but of another example embodiment of a medical device;

FIG. 5 is a partial cross sectional view similar to the view of FIG. 3,but of another example embodiment of a medical device;

FIG. 6 is a partial cross sectional view similar to the view of FIG. 3,but of another example embodiment of a medical device; and

FIG. 7 is a cross sectional view taken along line 7-7 of FIG. 1.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit the invention to theparticular embodiments described. On the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

DETAILED DESCRIPTION OF SOME EMBODIMENTS OF THE INVENTION

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about,” whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the terms “about” may include numbers thatare rounded to the nearest significant figure.

Weight percent, percent by weight, wt %, wt-%, % by weight, and the likeare synonyms that refer to the concentration of a substance as theweight of that substance divided by the weight of the composition andmultiplied by 100.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and5).

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The drawings, which are not necessarily to scale, depictillustrative embodiments and are not intended to limit the scope of theinvention.

Refer now to FIG. 1 which illustrates a medical device 10 in accordancewith one example embodiment. In the embodiment shown, the medical device10 is in the form of a guide or diagnostic catheter. Although set forthwith specific reference to a guide or diagnostic catheter in the exampleembodiments shown in the Figures and discussed below, the invention mayrelate to virtually any medical device including an elongate shaft ormember having a reinforcing member disposed thereon. For example, theinvention may be applied to medical devices such as a balloon catheter,an atherectomy catheter, a drug delivery catheter, a stent deliverycatheter, an endoscope, an introducer sheath (if the sheath includes areinforcing member), a fluid delivery device, other infusion oraspiration devices, device delivery (i.e. implantation) devices, and thelike. Thus, while the Figures and descriptions below are directed towarda guide or diagnostic catheter, in other applications sizes in terms ofdiameter and length may vary widely, depending upon the desiredproperties of a particular device. For example, in some devices, lengthsmay range from about 1-300 centimeters or more, while outside diametersmay range from about 1 F to about 20 F, or even more in someembodiments.

As shown in FIG. 1, the catheter 10 can include an elongate shaft 12including a proximal portion 16 having a proximal end 18, and distalportion 20 having a distal end 22. The shaft 12 is a generally tubularmember defining a lumen 15 therein. A manifold 14 can be connected tothe proximal end of the elongate shaft 12, and include a lumen and/orother structure to facilitate connection to other medical devices (e.g.,syringe, Y-adapter, etc.) and to provide access to lumen 15 within theshaft 12. The manifold may include a hub portion 17 and a strain reliefportion 19. In some embodiments, the shaft 12 may include additionaldevices or structures such as inflation or anchoring members, sensors,optical elements, ablation devices or the like, depending upon thedesired function and characteristics of the catheter 10.

The guide or diagnostic catheter 10 may have a length and an outsidediameter appropriate for its desired use, for example, to enableintravascular insertion and navigation. For example, the catheter 10 mayhave a length of about 20 cm-250 cm and an outside diameter ofapproximately 1 F-10 F, when catheter 10 is adapted as a guide catheter.In some embodiments, the catheter 10 can be a microcatheter that isadapted and/or configured for use within small anatomies of the patient.For example, some embodiments are particularly useful in treatingtargets located in tortuous and narrow vessels, for example in theneurovascular system, or in certain sites within the coronary vascularsystem, or in sites within the peripheral vascular system such assuperficial femoral, popliteal, or renal arteries. The target site insome embodiments is a neurovascular site, such as site in the brain,which is accessible only via a tortuous vascular path, for example, avascular path containing a plurality of bends or turns which may begreater than 90° turns, and/or involving vessels which are in the rangeof about 8 mm or less, and in some cases as small as 2-3 mm or less, indiameter. However, it is contemplated that the catheter may be used inother target sites within the anatomy of a patient. In some embodiments,the catheter can include an outside diameter in the range ofapproximately 1 F-4 F.

While in some embodiments, the catheter 10 can be described in terms ofintravascular use, in other embodiments the guide or diagnostic catheter10 may be suited for other uses in the digestive system, soft tissues,or any other use including insertion into an organism for medical uses.For example, in some embodiments, the catheter 10 may be significantlyshorter and used as an introducer sheath, for example, while in otherembodiments the catheter 10 may be adapted for other medical procedures.The guide or diagnostic catheter 10 may also include additionalstructure and materials that are substantially conventional.

Additionally, although depicted as including a generally roundcross-sectional shape, it can be appreciated that the shaft 12 caninclude other cross-sectional shapes or combinations of shapes withoutdeparting from the spirit of the invention. For example, thecross-sectional shape of the generally tubular shaft 12 may be oval,rectangular, square, triangular, polygonal, and the like, or any othersuitable shape, depending upon the desired characteristics.

Refer now to FIG. 2, which shows a partial cross sectional view of theshaft 12 including the proximal portion 16, the distal portion 20, andthe manifold 14 connected to the proximal end 18. The shaft 12 caninclude an inner tubular member 24 defining the lumen 15. The shaft 12can also include a reinforcing member 26 disposed about a portion of theinner tubular member 24, and a distal tip structure 28 disposed about adistal portion of the inner tubular member 24. Some example structuresand components for use in each of these structures will now be discussedin greater detail.

The inner tubular member 24 can extend from a point within the distalportion 20 to a point within the proximal portion 16 of the shaft 12.The length of the inner tubular member 24 can vary, depending upon, forexample, the length of the shaft 12, the desired characteristics andfunctions of the catheter 10, and other such parameters. In someembodiments, the inner tubular member 24 can extend substantially theentire length of the shaft 12, for example, from a point adjacent theproximal end 18 to a point adjacent the distal end 22. For example, thelength of the inner tubular member 24 can be in the range of about 1-300centimeters or more, or in some embodiments in the range of about 20cm-250 cm. In some embodiments, the inner tubular member 24 can includea proximal portion 33 and a distal portion 35, which can be any proximalor distal sections of the inner tubular member 24, but in some cases canbe defined with regard to the placement of the reinforcing member 26along the length of the inner tubular member. For example, in someembodiments, the distal portion 35 can be any portion of the innertubular member 24 that is distal of the reinforcing member 26, while theproximal portion 35 can be any portion of the inner tubular member 24that is disposed within, or is proximal of a distal end 39 ofreinforcing member 26. In some embodiments, the distal portion 35 canhave a length in the range of 1 cm or greater, or in the range of about2 cm or greater, and in some embodiments in the range of about 3 toabout 20 cm.

As indicated above, the inner tubular member 24 defines a lumen 15. Thelumen 15 can be adapted and/or configured to facilitate, for example,insertion of other medical devices (e.g., guide wires, ballooncatheters, etc.) there through, and/or to facilitate injection of fluids(e.g., radiopaque dye, saline, drugs, inflation fluid, etc.) therethrough. The size of the lumen can vary, depending upon the desiredcharacteristics and intended use. In some embodiments, the inner tubularmember 24 can have an inner diameter, defining the lumen 15, that is inthe range of about 0.01 to about 0.05 inch in size, and in someembodiments, in the range of about 0.015 to about 0.03 inch in size, andin some embodiments, in the range of about 0.016 to about 0.026 inch insize. Additionally, in some embodiments, the inner tubular member 24 canhave an outer diameter that is in the range of about 0.011 to about0.055 inch in size, and in some embodiments, in the range of about 0.015to about 0.03 inch in size, and in some embodiments, in the range ofabout 0.019 to about 0.029 inch in size. It should be understoodhowever, that these dimensions are provided by way of exampleembodiments only, and that in other embodiments, the size of the innerand outer diameter of the inner tubular member 24 can vary greatly fromthe dimensions given, depending upon the desired characteristics andfunction of the device. In some embodiments, the inner tubular member24, or other portions of the shaft 12, can define one or more additionallumens depending upon the desired characteristics and function of thecatheter 10, and such additional lumens can be shaped, size, adaptedand/or configured the same as or different from lumen 15, depending uponthe desired characteristic and functions.

The inner tubular member 24 may be one or more layers. As best seen inFIG. 3, the inner tubular member 24 may be multi-layered. In theillustrative embodiment, the inner tubular member 24 may include anouter layer 30, and an inner layer 34. It should be understood that moreor fewer layers can be used depending upon the desired characteristicsof the device. Furthermore, while an outer layer 30 and inner layer 34are described with respect to the particular embodiment, these layers30, 34 may be provided as a single layer. For example, the inner layer34 and outer layer 30 may be provided separately, but attached orcombined together to physically form a single layer.

Inner layer 34 and outer layer 30 may be made of any suitable materialand by any suitable process, the materials and processes varying withthe particular application. Examples of some suitable materials include,but are not limited to, polymers, metals, metal alloys, or composites orcombinations thereof. Some examples of some suitable polymers caninclude, but are not limited to, polyoxymethylene (POM), polybutyleneterephthalate (PBT), polyether block ester, polyether block amide(PEBA), fluorinated ethylene propylene (FEP), polyethylene (PE),polypropylene (PP), polyvinylchloride (PVC), polyurethane,polytetrafluoroethylene (PTFE), polyether-ether ketone (PEEK),polyimide, polyamide, polyphenylene sulfide (PPS), polyphenylene oxide(PPO), polysulfone, nylon, perfluoro(propyl vinyl ether) (PFA),polyether-ester, polymer/metal composites, etc., or mixtures, blends orcombinations thereof, and may also include or be made up of a lubricouspolymer. One example of a suitable polyether block ester is availableunder the trade name ARNITEL, and one suitable example of a polyetherblock amide (PEBA) is available under the trade name PEBAX®, fromATOMCHEM POLYMERS, Birdsboro, Pa.

The inner layer 34 may include a lubricious polymer such as HDPE orPTFE, for example, or a copolymer of tetrafluoroethylene withperfluoroalkyl vinyl ether (PFA) (more specifically, perfluoropropylvinyl ether or perfluoromethyl vinyl ether), or the like. The outerlayer 30 may include a flexible polymer such as polyether block amide orpolyether-ester elastomer. Additionally, in some embodiments, thepolymer material of the inner layer 34 and/or outer layer 30 can beblended with a liquid crystal polymer (LCP). For example, in someembodiments, the mixture can contain up to about 5% LCP. This has beenfound in some embodiments to enhance torqueability.

Additionally, as suggested above, in some embodiments, the inner tubularmember 24 may include or be made of metal or metal alloys. Some examplesof suitable metals and metal alloys can include stainless steel, such as304V, 304L, and 316L stainless steel; nickel-titanium alloy such as asuperelastic (i.e. pseudoelastic) or linear elastic nitinol;nickel-chromium alloy; nickel-chromium-iron alloy; cobalt alloy;tungsten or tungsten alloys; tantalum or tantalum alloys, gold or goldalloys, MP35-N (having a composition of about 35% Ni, 35% Co, 20% Cr,9.75% Mo, a maximum 1% Fe, a maximum 1% Ti, a maximum 0.25% C, a maximum0.15% Mn, and a maximum 0.15% Si); or the like; or other suitablemetals, or combinations or alloys thereof. In some embodiments, it isdesirable to use metals, or metal alloys that are suitable for metaljoining techniques such as welding, soldering, brazing, crimping,friction fitting, adhesive bonding, etc.

The inner tubular member 24 can be formed by any suitable method ortechnique. For example in some embodiments, the inner layer 34 can beformed separately, and thereafter the outer layer 30 can be disposedthereon by suitable techniques, such as extrusion, co-extrusion,interrupted layer co-extrusion (ILC), coating, heat shrink techniques,casting, molding, or by fusing one or several segments of an outer layermaterial end-to-end about the inner layer 34, or the like. In some otherembodiments, the layers 30/34 may be formed together using suitabletechniques, such as extrusion, co-extrusion, interrupted layerco-extrusion (ILC), heat shrink techniques, fusing, or the like. In yetother embodiments, the layers 30/34 can be formed separately, such as byextrusion, co-extrusion, interrupted layer co-extrusion (ILC), casting,molding, heat shrink techniques, fusing, or the like, and thereaftercoupled or connected together using suitable techniques, such as heatshrink techniques, friction fitting, mechanically fitting, chemicallybonding, thermally bonding, welding (e.g., resistance, Rf, or laserwelding), soldering, brazing, adhesive bonding, crimping, or the use ofa connector member or material, or the like, or combinations thereof.

The inner tubular member 24 may have a uniform stiffness, or may vary instiffness along its length. For example, a gradual reduction instiffness from the proximal end to the distal end thereof may beachieved, depending upon the desired characteristics. The gradualreduction in stiffness may be continuous or may be stepped, and may beachieved, for example, by varying the structure, such as the size orthickness of one or more of the layers 30/34, or for example, by varyingthe materials used in one or more of the layers 30/34. Such variabilityin characteristics and materials can be achieved, for example, by usingtechniques such as ILC, or by fusing together separate extruded tubularsegments. Additionally, the inner and/or the outer layer, 34/30 or both,may be impregnated with, or be made of or include a radiopaque materialto facilitate radiographic visualization. Radiopaque materials areunderstood to be materials capable of producing a relatively brightimage on a fluoroscopy screen or another imaging technique during amedical procedure. This relatively bright image aids the user ofcatheter 10 in determining its location. Some examples of radiopaquematerials can include, but are not limited to, gold, platinum,palladium, tantalum, tungsten alloy, polymer material loaded withradiopaque filler, and the like. Likewise, in some embodiments, theinner and/or the outer layer, 34/30 or both, may be impregnated with, orbe made of or include a material that may aid in MRI imaging. Somematerials that exhibit these characteristics include, for example,tungsten, Elgiloy, MP35N, nitinol, and the like, and others. Thoseskilled in the art will recognize that these materials can vary widelywithout departing from the spirit of the invention.

Additionally, although depicted as including a generally roundcross-sectional shape, it can be appreciated that the inner tubularmember 24 can include other cross-sectional shapes or combinations ofshapes without departing from the spirit of the invention. For example,the cross-sectional shape of the inner tubular member 24 may be oval,rectangular, square, triangular, polygonal, and the like, or any othersuitable shape, depending upon the desired characteristics.

Referring to FIGS. 2 and 3, the reinforcing member 26 can also be agenerally tubular member including a proximal region 36 having aproximal end 37 and a distal region 38 having a distal end 39. Thereinforcing member 26 can be disposed about at least a portion of theinner tubular member 24 at a location along the length of the shaft 12between proximal end 18 and distal end 22. In the embodiment shown, thereinforcing member 26 is disposed about the inner tubular member 26along the proximal portion 16 of the shaft 12, but it should beunderstood that other locations are possible. The length of thereinforcing member 26 can also vary, depending upon, for example, thelength of the shaft 12, the desired characteristics and functions of thecatheter 10, and other such parameters. In some embodiments, thereinforcing member 26 has a length that allows it to be disposed overthe majority of the length of the inner tubular member 24, and in someembodiments, is disposed about all but up to the distal most 15 cm orless of the inner tubular member 24. For example, the length of theinner tubular member 24 can be in the range of about 1-299 centimetersor more, or in some embodiments in the range of about 19 cm-249 cm.

Referring to FIG. 3, the reinforcing member 26 defines a lumen 40 thatcan be adapted and/or configured to house or surround a portion of theinner tubular member 24. In some embodiments, the reinforcing member 26can have an inner diameter, defining the lumen 40, that is in the rangeof about 0.015 to about 0.06 inch in size, and in some embodiments, inthe range of about 0.02 to about 0.035 inch in size. Additionally, insome embodiments, the reinforcing member 26 can have an outer diameterthat is in the range of about 0.016 to about 0.07 in size, and in someembodiments, in the range of about 0.02 to about 0.04 inch in size. Itshould be understood however, that these, and other dimensions providedherein, are by way of example embodiments only, and that in otherembodiments, the size of the inner and outer diameter of the reinforcingmember 26 can vary greatly from the dimensions given, depending upon thedesired characteristics and function of the device.

The reinforcing member 26 typically has an inner diameter that isgreater than the outer diameter of the inner tubular member 24. As such,the reinforcing member 26 can be disposed about the inner tubular member24 (i.e. a portion of the inner tubular member 24 is disposed within thelumen 40 of the reinforcing member) such that a space or gap 42 isdefined between at least a portion of the outer surface 25 of the innertubular member 24 and the inner surface 27 of the reinforcing member 26.In some embodiments, the space or gap 42 between at least a portion ofthe outer surface 25 of the inner tubular member 24 and the innersurface 27 of the reinforcing member 26 is in the range of about 0.0002to about 0.004 inch in size, and in some embodiments, in the range ofabout 0.0005 to about 0.003 inch in size. It should be understoodhowever, that these, and other dimensions provided herein, are by way ofexample embodiments only, and that in other embodiments, the size of thespace or gap 42 can vary greatly from the dimensions given, dependingupon the desired characteristics and function of the device.

Typically, the gap or space 42 remains open or unfilled by any otherstructure of the catheter along substantially the entire length of thereinforcing member 26, with the exception of small coupling pointsadjacent the proximal and distal ends 37/39 of the reinforcing member,for example, as will be set forth in more detail below. For example, insome embodiments, the gap or space 42 can extend between the outersurface 25 of the inner tubular member 24 and the inner surface 27 ofthe reinforcing member 26 along the length of the reinforcing member 26in the range of about 50% or greater, 75% or greater, 90% or greater, or95% or greater of the entire length of the reinforcing member 26.However, in other embodiments, other attachment points along the lengthof the reinforcing member 26 may be used, and as a result, multiple gapsor spaces may be created that may be separated by these additionalattachment points, which may, in effect, fill portions of the gap 42.Still, such multiple gaps or spaces may still collectively extend alonga substantial portion of the length of the reinforcing member, forexample, in percentages of the total length as given above. As such, thereinforcing member 26 can act to reinforce or impart desired properties,such as tortional and lateral rigidity, to the catheter shaft 12, butallow at least the portion of the inner tubular member 24 surrounded bythe gap or space 42 to move laterally within the lumen 40. Some examplesof structure, methods, and techniques of coupling the reinforcing member26 to the inner tubular member 24 will be discussed in more detailbelow.

The reinforcing member 26 can be adapted and/or configured to have adesired level of stiffness, torqueability, flexibility, and/or othercharacteristics. Those of skill in the art and others will recognizethat the dimensions, structure, and materials of the reinforcing member26 are dictated primarily by the desired characteristics, and thefunction of the final catheter 10, and that any of a broad range of thedimensions, structure, and materials can be used.

The desired stiffness, torquability, lateral flexibility, bendability orother such characteristics of the reinforcing member 26 can be impartedor enhanced by the structure of the reinforcing member 26. For example,the reinforcing member 26 may include a thin wall tubular structure,including one or a plurality of apertures 44, such as grooves, cuts,slits, slots, or the like, formed in a portion of, or along the entirelength of, the tubular reinforcing member 26. Such structure may bedesirable because it may allow reinforcing member 26, or portionsthereof, to have a desired level of lateral flexibility as well as havethe ability to transmit torque and pushing forces from the proximalregion 36 to the distal region 38. The apertures 44 can be formed inessentially any known way. For example, apertures 44 can be formed bymethods such as micro-machining, saw-cutting, laser cutting, grinding,milling, casting, molding, chemically etching or treating, or otherknown methods, and the like. In some such embodiments, the structure ofthe reinforcing member 26 is formed by cutting and/or removing portionsof the tube to form apertures 44.

In some embodiments, the apertures 44 can completely penetrate thereinforcing member 26 such that there is fluid communication between thelumen 40 and the exterior of the reinforcing member 26 through theapertures 44. In some embodiments, the apertures 44 may only partiallyextend into the structure of the reinforcing member 26, either on theinterior or exterior surface thereof. Some other embodiments may includecombinations of both complete and partial apertures 44 through thestructure of the reinforcing member 26. The shape and size of theapertures 44 can vary, for example, to achieve the desiredcharacteristics. For example, the shape of apertures 44 can vary toinclude essentially any appropriate shape, such as squared, round,rectangular, pill-shaped, oval, polygonal, elongated, irregular, or thelike, and may include rounded or squared edges, and can be variable inlength and width, and the like.

Additionally, the spacing, arrangement, and/or orientation of theapertures 44, or in some embodiments, associated spines or beams thatmay be formed, can be varied to achieve the desired characteristics. Forexample, the number or density of the apertures 44 along the length ofthe reinforcing member 26 may vary, depending upon the desiredcharacteristics. For example, the number or proximity of apertures 44 toone another near one end of the reinforcing member 26 may be high, whilethe number or proximity of slots to one another near the other end ofthe reinforcing member 26, may be relatively low, or vice versa. Forexample, in the embodiment shown in FIGS. 1 and 2, the distal region 38of the reinforcing member 26 includes a plurality of apertures 44, whilethe proximal region 36 of the reinforcing member 26 does not include anyapertures 44. As such, the distal region 38 can have a greater degree oflateral flexibility relative to the proximal region 36. In someembodiments, the distal about 10 to about 50% of the total length of thereinforcing member 26 can include apertures 44 defined therein, whilethe proximal about 50 to about 90% of the total length of thereinforcing member 26 is free of such apertures 44. For example, in someembodiments, the distal region 38 having a length in the range of about30 to about 70 cm includes apertures 44 defined therein, while theremaining length in the proximal region 36 of the reinforcing member isfree of such apertures 44. It should be understood however, that these,and other dimensions provided herein, are by way of example embodimentsonly, and that in other embodiments, the disposition of apertures 44 canvary greatly from the dimensions given, depending upon the desiredcharacteristics and function of the device.

As suggested above, the apertures 44 may be formed such that one or morespines or beams 29 are formed in the tubular reinforcing member 26. Suchspines or beams 29 (See FIGS. 2-6) could include portions of the tubularmember 26 that remain after the apertures 44 are formed in the body ofthe tubular member. Such spines or beams 29 may act to maintain arelatively high degree of tortional stiffness, while maintaining adesired level of lateral flexibility. In some embodiments, some adjacentapertures 44 can be formed such that they include portions that overlapwith each other about the circumference of the tube. In otherembodiments, some adjacent apertures 44 can be disposed such that theydo not necessarily overlap with each other, but are disposed in apattern that provides the desired degree of lateral flexibility.Additionally, the apertures 44 can be arranged along the length of, orabout the circumference of, the reinforcing member 26 to achieve desiredproperties. For example, the apertures 44 can be arranged in asymmetrical pattern, such as being disposed essentially equally onopposite sides about the circumference of the reinforcing member 26, orequally spaced along the length of the reinforcing member, or can bearranged in an increasing or decreasing density pattern, or can bearranged in a non-symmetric or irregular pattern.

Collectively, these figures and this description illustrate that changesin the arrangement, number, and configuration of slots may vary withoutdeparting from the scope of the invention. Some additional examples ofarrangements of cuts or slots formed in a tubular body are disclosed inU.S. Pat. No. 6,428,489 and in Published U.S. patent application Ser.No. 09/746,738 (Pub. No. 2002/0013540), now U.S. Pat. No. 6,579,246,both of which are incorporated herein by reference. Also, someadditional examples of arrangements of cuts or slots formed in a tubularbody for use in a medical device are disclosed in U.S. patentapplication Ser. No. 10/375,493, now published as U.S. PatentApplication Publication No. 2004/0167437, which is also incorporatedherein by reference.

In addition to, or as an alternative to the structure of the reinforcingmember 26, the materials selected for reinforcing member 26 may bechosen so that it has the desired characteristics. For example,reinforcing member 26 may be formed of materials having a desiredmodulus of elasticity. The reinforcing member 26 may be formed of anymaterials suitable for use, dependent upon the desired properties of thecatheter 10. Some examples of suitable materials include metals, metalalloys, polymers, or the like, or combinations or mixtures thereof. Someexamples of suitable metals and metal alloys include stainless steel,such as 304V, 304L, and 316L stainless steel; alloys includingnickel-titanium alloy such as linear elastic or superelastic (i.e.pseudoelastic) nitinol; nickel-chromium alloy; nickel-chromium-ironalloy; cobalt alloy; tungsten or tungsten alloys; MP35-N (having acomposition of about 35% Ni, 35% Co, 20% Cr, 9.75% Mo, a maximum 1% Fe,a maximum 1% Ti, a maximum 0.25% C, a maximum 0.15% Mn, and a maximum0.15% Si); hastelloy; monel 400; inconel 625; or the like; or othersuitable material, or combinations or alloys thereof. In someembodiments, it is desirable to use metals, or metal alloys that aresuitable for metal joining techniques such as welding, soldering,brazing, crimping, friction fitting, adhesive bonding, etc.Additionally, in some embodiments, the reinforcing member 26 may be madeof or include, be coated, plated, or clad with a radiopaque or MRIimaging material to facilitate radiographic visualization or MRIimaging.

The word nitinol was coined by a group of researchers at the UnitedStates Naval Ordinance Laboratory (NOL) who were the first to observethe shape memory behavior of this material. The word nitinol is anacronym including the chemical symbol for nickel (Ni), the chemicalsymbol for titanium (Ti), and an acronym identifying the Naval OrdinanceLaboratory (NOL). In some embodiments, nitinol alloys can include in therange of about 50 to about 60 weight percent nickel, with the remainderbeing essentially titanium. It should be understood, however, that inother embodiment, the range of weight percent nickel and titanium, andor other trace elements may vary from these ranges. Within the family ofcommercially available nitinol alloys, are categories designated as“superelastic” (i.e. pseudoelastic) and “linear elastic” which, althoughsimilar in chemistry, exhibits distinct and useful mechanicalproperties.

In some embodiments, a superelastic alloy, for example a superelasticnitinol can be used to achieve desired properties. Such alloys typicallydisplay a substantial “superelastic plateau” or “flag region” in itsstress/strain curve. Such alloys can be desirable in some embodimentsbecause a suitable superelastic alloy will provide a reinforcing member26 that is exhibits some enhanced ability, relative to some othernon-superelastic materials, of substantially recovering its shapewithout significant plastic deformation, upon the application andrelease of stress, for example, during placement of the catheter in thebody.

In some other embodiments, a linear elastic alloy, for example a linearelastic nitinol can be used to achieve desired properties. For example,in some embodiments, certain linear elastic nitinol alloys can begenerated by the application of cold work, directional stress, and heattreatment, such that the material fabricated does not display asubstantial “superelastic plateau” or “flag region” in its stress/straincurve. Instead, in such embodiments, as recoverable strain increases,the stress continues to increase in a somewhat linear relationship untilplastic deformation begins. In some embodiments, the linear elasticnickel-titanium alloy is an alloy that does not show anymartensite/austenite phase changes that are detectable by DSC and DMTAanalysis over a large temperature range. For example, in someembodiments, there is no martensite/austenite phase changes detectableby DSC and DMTA analysis in the range of about −60° C. to about 120° C.The mechanical bending properties of such material are thereforegenerally inert to the effect of temperature over a broad range oftemperature. In some particular embodiments, the mechanical propertiesof the alloy at ambient or room temperature are substantially the sameas the mechanical properties at body temperature. In some embodiments,the use of the linear elastic nickel-titanium alloy allows thereinforcing member to exhibit superior “pushability” around tortuousanatomy. One example of a suitable nickel-titanium alloy exhibiting atleast some linear elastic properties is FHP-NT alloy commerciallyavailable from Furukawa Techno Material Co. of Kanagawa, Japan.Additionally, some examples of suitable nickel-titanium alloy exhibitingat least some linear elastic properties include those disclosed in U.S.Pat. Nos. 5,238,004 and 6,508,803, which are incorporated herein byreference.

In some embodiments, the reinforcing member 26 can be formed of ashape-memory material, for example a shape memory alloy such as a shapememory nitinol. In such embodiments, the shape memory effect can be usedin the deployment or use of the catheter, for example in causing thereinforcing member 26 to move from a first insertion configuration to asecond use configuration, or, for example, for the reinforcing member 26to “remember” its desired shape after deformation to another shape.

For example, in some embodiments, the reinforcing member 26 can includeor be made of a shape memory alloy that is martensite at roomtemperature, and has a final austenite transition temperature (A_(f))somewhere in the temperature range between room temperature and bodytemperature. For example, in some such embodiments, the shape memoryalloy has a final austenite transition temperature in the range of about25° C. and about 37° C. (e.g. body temperature). In some suchembodiments, it may be desirable that the final austenite transitiontemperature be at least slightly below body temperature, to ensure finaltransition at body temperature. This feature allows the reinforcingmember 26 to be inserted into the body of a patient in a martensiticstate, and assume its preformed, austenitic shape when exposed to thehigher body temperature within the anatomy, or at the target site. Inthis embodiment, deployment of the reinforcing member 26 can be achievedby a shape memory effect—as the material warms, it undergoes atransition from martensite to austenite form, causing transformation ofthe reinforcing member 26 from the first configuration to the secondconfiguration.

In other example embodiments, the reinforcing member 26 can include orbe made of a shape-memory alloy that could have a transition temperatureM_(d) (wherein M_(d)=highest temperature to strain-induced martensite)that is in the range of body temperature (e.g. 37° C.) or greater, belowwhich the alloy retains sufficient stress-induced martensitic propertyto allow placement of the reinforcing member 26 at or above its finalaustenite transition temperature (A_(f)). In other words, this allowsthe catheter, including the reinforcing member 26 in its preformedaustenitic state, to be inserted and navigated in the anatomy, where thereinforcing member may be exposed to stress that may promote portionsthereof to undergo stress-induced martensitic (SIM) transformation.Thereafter, the reinforcing member 26 may recover its preformed,austenitic shape when released from the stress of navigation, at atemperature that may be substantially above the final austenitetransition temperature without significant plastic, or otherwisepermanent deformation. Additionally, in some such embodiments, thereinforcing member 26 can be constrained, for example, in a deliverydevice, such as a guide catheter, in a stress-induced martensitic (SIM)state, and recover its preformed, austenitic shape when released fromthe constraints of the catheter, at a temperature that may besubstantially above the final austenite transition temperature withoutsignificant plastic, or otherwise permanent deformation. In theseembodiments, the final austenite temperature may be quite low, e.g., 4°C. or lower, or it may be up to room temperature or higher.

In yet other embodiments, the reinforcing member 26 can include or bemade of a shape memory alloy that is martensite at body temperature, andhas a final austenite transition temperature (A_(f)) somewhere in thetemperature range above body temperature. This feature allows thecatheter including the reinforcing member 26 to be navigated in amartensitic state, and maintain a martensitic state until exposed to atemperature higher than body temperature. The reinforcing member 26 canthen be heated to the necessary temperature above body temperature tomake the transformation from martensite to austenite using an externalheating means or mechanism. Such mechanisms may include the injection ofheated fluid through the catheter, or other device, the use ofelectrical or other energy to heat the reinforcing member 26, or othersuch techniques. In some such embodiments, the shape memory alloy has afinal austenite transition temperature in the range of about 37° C. toabout 45° C. It may be desirable that the final austenite transitiontemperature be at least slightly above body temperature, to ensure thereis not final transition at body temperature. Some examples of Nitinolcylindrical tubes having desired transition temperatures, as notedabove, can be prepared according to known methods.

As noted above, the reinforcing member 26 may also be formed of orinclude polymer materials. Some examples of polymeric materials mayinclude, but are not limited to: poly(L-lactide) (PLLA),poly(D,L-lactide) (PLA), polyglycolide (PGA),poly(L-lactide-co-D,L-lactide) (PLLA/PLA), poly(L-lactide-co-glycolide)(PLLA/PGA), poly(D, L-lactide-co-glycolide) (PLA/PGA),poly(glycolide-co-trimethylene carbonate) (PGA/PTMC), polyethylene oxide(PEO), polydioxanone (PDS), polycaprolactone (PCL), polyhydroxylbutyrate(PHBT), poly(phosphazene), polyD,L-lactide-co-caprolactone) (PLA/PCL),poly(glycolide-co-caprolactone) (PGA/PCL), polyanhydrides (PAN),poly(ortho esters), poly(phoshate ester), poly(amino acid), poly(hydroxybutyrate), polyacrylate, polyacrylamid, poly(hydroxyethyl methacrylate),polyurethane, polysiloxane and their copolymers, or mixtures orcombinations thereof.

Referring now to FIG. 3, the distal portion 20 of the shaft 12 caninclude a distal region of the inner tubular member 24, and, in someembodiments, additional structure that can be adapted and/or configuredto provide a distal tip structure 28 on the distal region of thecatheter 10. For example, the distal tip structure 28 can be adaptedand/or configured to provide characteristics such as shapability,flexability, steerability, atraumatic characteristics, and the like. Forexample, distal portion 20 including the inner tubular member 24, canalso include one or more additional layers in addition to or disposed onthe inner tubular member 24. Such additional layers may be made of anysuitable material and by any suitable process, the materials andprocesses varying with the particular application and characteristicsdesired. For example, in the embodiment shown in FIG. 3, which is apartial cross-sectional view of a portion of the shaft 12, the distalportion 20 can include two additional layers 50 and 52 disposed aboutthe inner tubular member 24. In the embodiment shown, an inner layer 50,which may be a reinforcement layer, such as a coil, braid, or the like,is disposed about the distal region of the inner tubular member 24, andan outer layer 52, such as a sleeve of material, for example, a polymersleeve or layer, is disposed about the reinforcement layer 50 and theinner tubular member 24. It should be understood that in someembodiments it is not necessary that one or more of the layers include areinforcing structure such as a coil or braid. It should also beunderstood that more or fewer layers can be used depending upon thedesired characteristics of the device. Additionally, in someembodiments, a reinforcement layer 50 or structure, such as a coil orbraid, may be embedded within a layer, or disposed between multiplelayers.

Referring to FIG. 3, the reinforcement layer 50 illustrated can be acoil that has a generally circular cross-sectional shape, and isappropriately sized for disposal about the distal region of the shaft12. A broad variety of other shapes and sizes could be used, forexample, depending upon the size and shape of the distal region of theshaft. The coil 50 can be formed of a variety of materials includingmetals, metal alloys, polymers, and the like, for example, thosematerials discussed above with regard to the reinforcing member 26.

The coil 50 can be formed of round wire or flat ribbon ranging indimensions to achieve the desired flexibility. In some embodiments, thecoil 50 can be a round ribbon in the range of about 0.001-0.015 inchesin diameter, and can have a length in the range of about 0.1 to about 20cm; however, other dimensions and length are contemplated. The coil 50can be wrapped in a helical fashion by conventional winding techniques.The pitch of adjacent turns of the coil 50 may be tightly wrapped sothat each turn touches the succeeding turn or the pitch may be set suchthat the coil 50 is wrapped in an open fashion. Additionally, in someembodiments, the coil 50 or portions thereof can be made of or includeor be coated, plated, or clad with a radiopaque or imaging material, asdiscussed above. Additionally, other radiopaque or MRI imagingstructures can be incorporated into the structure of the distal portion20, or other parts of the shaft 12. For example, a band, coil, ring, orother such structure made of or including radiopaque or MRI imagingmaterial may be disposed about or within a portion of the shaft, forexample, radiopaque or MRI ring 60. Such a structure can be incorporatedwithin or disposed on the shaft using suitable techniques such asadhesive bonding, crimping, friction fitting, mechanically fitting,chemically bonding, thermally bonding, welding (e.g., resistance, Rf, orlaser welding), soldering, brazing, or the use of a connector member ormaterial, or the like, or combinations thereof.

The outer layer 52 can be a sheath or sleeve of material, such as apolymer material, disposed about the coil 50 and the inner tubularmember 24. Some examples of suitable polymer materials include thoselisted above with regard to the inner tubular member, and the like. Theouter layer 52 can be constructed and disposed using any appropriatetechnique, for example, by extrusion, co-extrusion, interrupted layerco-extrusion (ILC), coating, heat shrink techniques, heat bonding,casting, molding, fusing one or several segments of an outer layermaterial end-to-end, or the like. Securing the outer layer 52 to thecoil 50 and/or the inner tubular member 24 may be achieved by the use ofthe above techniques, or in embodiments where the layer 52 isconstructed independently of the other portions of the shaft 12, may bethereafter secured to the coil 50 and/or the inner tubular member 24using suitable techniques such as adhesive bonding, crimping, frictionfitting, mechanically fitting, chemically bonding, thermally bonding,welding (e.g., resistance, Rf, or laser welding), soldering, brazing, orthe use of a connector member or material, or the like, or combinationsthereof. Additionally, the outer layer 52 may be sized such that atleast the portion thereof that is adjacent the reinforcing member has anouter diameter that is about the same as the outer diameter of thereinforcing member 26, so as to maintain a generally constant diameterin the transition between the reinforcing member 26 and the outer layer52. Additionally, in some embodiments, the outer layer may include aportion that overlaps the distal end of the reinforcing member 26 toprovide a smooth transition. In other embodiments, however, a tapered orstep down transition may be provided. The distal portion 15 of theelongate shaft 12 may be curved as desired, or be adapted and/orconfigured to be curved as desired, depending on the particularapplication.

Now some example embodiments of structure, methods, and techniques ofcoupling structure of the catheter 10, such as the manifold 14,reinforcing member 26, and distal tip structure 28 to the inner tubularmember 24, will be discussed in more detail.

Refer now to FIG. 3, which illustrates one example embodiment of aportion of a catheter shaft 12, including the inner tubular member 24,the reinforcing member 26, and the distal tip structure 28 as discussedabove. The distal region 36 of the reinforcing member 26 can beconnected to the inner tubular member 24 using suitable techniques suchas adhesive bonding, friction fitting, mechanically fitting, crimping,chemically bonding, thermally bonding, welding (e.g., resistance, Rf, orlaser welding), soldering, brazing, or the use of a connector member ormaterial, or the like, or combinations thereof. In the embodiment shown,the distal end 39 of the reinforcing member 26 can be connected to theinner tubular member 24 using an adhesive material 62, for example, acyanoacrylate, or other suitable type of adhesive. In at least someembodiments, only a relatively small portion of the distal region 38adjacent the distal end 39 of the reinforcing member 26 is connected tothe inner tubular member 24. For example, the adhesive or other materialor structure used to make the connection may only extend under or withinfive or fewer of the apertures 44, or in some embodiments, as shown inFIG. 3, three or even two or fewer of the apertures 44. The coil 50 canbe slid onto the distal region 38 of the inner tubular member 24, suchthat it is in line with or butts up to the reinforcing member 26, andcan be connected to the inner tubular member 24 using suitabletechniques, such as those described above. In some embodiments, thereinforcing member and the coil 50 can be connected to the inner tubularmember 24 at the same time and/or using the same attachment material,such as an adhesive. In other embodiments, they may be attachedseparately and/or using separate attachment techniques. Any radiopaqueor MRI structures, such as the ring 60, can be attached to the coil 50,using suitable attachment techniques, as discussed above. For example,the ring 60 may be attached to the coil 50 by crimping the ring to thecoil adjacent the distal end 39 of the reinforcing member 26. In such aconfiguration, the placement of the ring 60 may also aid in providing amore gradual transition or step down in diameter from the reinforcingmember 26 to the coil 50. The outer layer 52, such as a polymermaterial, can be disposed about the ring 60, the coil 50 and the innertubular member 24. As discussed above, the outer layer 52 may be sizedappropriately so as to maintain a generally constant diameter in thetransition between the reinforcing member 26 and the outer layer 52, andmay include portion 65 that overlaps the distal end of the reinforcingmember 26 to provide a smooth transition.

Refer now to FIG. 4, which shows an alternative construction similar tothat shown in FIG. 3, wherein similar elements are numbered the same. InFIG. 4, however, a ring 70 of material, such as polymer material, heatshrink material, or the like, is disposed about the inner tubular member24 under the distal end 39 of the reinforcing member 26. In suchembodiments, the use of the ring 70 disposed between the inner tubularmember 24 and the reinforcing member 26 can aid in maintaining thebonding and integrity of the joint or connection.

Refer now to FIG. 5, which shows another alternative constructionsimilar to that shown in FIG. 3, wherein similar elements are numberedthe same. In FIG. 5, however, the ring 60 is absent. Additionally, inthis embodiment, the coil 50 extends proximally such that a proximalportion of the coil 50 is disposed about the inner tubular member 24under the distal end 39 of the reinforcing member 26. In suchembodiments, the placement of a proximal portion of the coil 50 betweenthe inner tubular member 24 and the reinforcing member 26 can aid inmaintaining the bonding and integrity of the joint or connection. Thisembodiment also shows a continuous layer of adhesive material 62 that isused to connect the reinforcing member 26 and the coil 50 to the innertubular member 24. The outer layer 52 can be disposed about the coil 50,the adhesive material 62, and the inner tubular member 24, and may alsoinclude a portion 65 that overlaps the distal end of the reinforcingmember 26 to provide a smooth transition.

Refer now to FIG. 6, which shows another alternative constructionsimilar to that shown in FIG. 3, wherein similar elements are numberedthe same. In FIG. 6, however, the ring 60 is absent. Additionally, thisembodiment shows a continuous layer of adhesive material 62 that is usedto connect the reinforcing member 26 and the coil 50 to the innertubular member 24, and also includes an outer layer 52 that includes acutout or stepped up portion 80 that can accommodate a greater amount ofadhesive material. In some embodiments, the adhesive material may alsoact to connect the outer layer 52 to the shaft 12.

Referring back to FIGS. 1 and 2, at the proximal end of the shaft 12,the manifold 14 may be secured to the inner tubular member 24 and/or thereinforcing member 26 at the proximal end 18 of the shaft 12 using anysuitable technique, for example, by adhesive, friction fitting,mechanically fitting, chemically bonding, thermally bonding, heat shrinkmaterials, molding, casting, welding (e.g., resistance or laserwelding), soldering, brazing, the use of an outer sleeve or polymerlayer to bond or connect the components, or the like, or combinationsthereof. In some embodiments, the distal end of the manifold 14 can becast, molded or shaped onto the proximal end 18 of the shaft 12 suchthat it is connected to the proximal end 18, and can also act as aconnector between the inner tubular member 24 and/or the reinforcingmember 26. For example, the manifold may be made of a polymericmaterial, such as a polycarbonate material, or the like, that could bemolded or cast onto the proximal end 18 of the shaft 12. For example,refer now to FIG. 7, which shows the manifold 14 attached to theproximal end 18 of the shaft 12. The manifold 14 can be cast, molded orshaped onto the proximal end 18 of the shaft 12 such that it can includea protrusion 91 that extends between and interconnects the inner tubularmember 24 and the reinforcing member 26, and may also include anoverlapping portion 93 that may help to maintain connection, and mayprovide a smooth transition between the manifold 14 and thereinforcement member 26.

A lubricious, a hydrophilic, a protective, or other type of coating maybe applied over portions or all of the shaft 12. Hydrophobic coatingssuch as fluoropolymers provide a dry lubricity which improves catheterhandling and device exchanges. Lubricious coatings can aid in insertionand steerability. Suitable lubricious polymers are well known in the artand may include silicone and the like, hydrophilic polymers such aspolyarylene oxides, polyvinylpyrolidones, polyvinylalcohols, hydroxyalkyl cellulosics, algins, saccharides, caprolactones, and the like, andmixtures and combinations thereof. Hydrophilic polymers may be blendedamong themselves or with formulated amounts of water insoluble compounds(including some polymers) to yield coatings with suitable lubricity,bonding, and solubility. Some other examples of such coatings andmaterials and methods used to create such coatings can be found in U.S.Pat. Nos. 6,139,510 and 5,772,609, which are incorporated herein byreference.

It should also be understood that in some embodiments, a degree of MRIcompatibility can be imparted into catheter 10. For example, to enhancecompatibility with Magnetic Resonance Imaging (MRI) machines, it may bedesirable to construct portions of the reinforcing member 26, the coil50, or other portions of the catheter 10, in a manner, or use materialsthat would impart, a degree of MRI compatibility. For example, thelengths of relatively conductive structures within the catheter 10 maybe limited to lengths that would not generate undue heat due toresonance waves created in such structures when under the influence ofan MRI field generated by an MRI machine. Alternatively, oradditionally, portions, or all of the catheter may be made of a materialthat does not substantially distort the image and create substantialartifacts (artifacts are gaps in the image). Certain ferromagneticmaterials, for example, may not be suitable because they may createartifacts in an MRI image. Additionally, all or portions of the cathetermay also be made from a material that the MRI machine can image, asdescribed above. Some materials that exhibit these characteristicsinclude, for example, tungsten, Elgiloy, MP35N, nitinol, and the like,and others.

The present invention should not be considered limited to the particularexamples described above, but rather should be understood to cover allaspects of the invention as fairly set out in the attached claims.Various modifications, equivalent processes, as well as numerousstructures to which the present invention may be applicable will bereadily apparent to those of skill in the art to which the presentinvention is directed upon review of the instant specification. Itshould be understood that this disclosure is, in many respects, onlyillustrative. Changes may be made in details, particularly in matters ofshape, size, and arrangement of steps without exceeding the scope of theinvention. The scope of the invention is, of course, defined in thelanguage in which the appended claims are expressed.

What is claimed is:
 1. A medical device, comprising: an elongate shafthaving a distal end; wherein the shaft has a plurality of slots formedtherein; a liner disposed within the shaft, the liner having a distalregion disposed distally of the distal end of the shaft; a tip membercoupled to the distal region of the liner; a hub coupled to the shaftand to the liner; wherein the hub is coupled to the shaft at a firstattachment region; and wherein the hub is coupled to the liner at asecond attachment region radially spaced from the first attachmentregion so that the shaft and the liner are radially spaced adjacent tothe hub; wherein the first attachment region and the second attachmentregion are both disposed distal to any structure of the hub that isdesigned to be connectable to another medical device.
 2. The medicaldevice of claim 1, wherein a hub projection is positioned between thefirst attachment region and the second attachment region.
 3. The medicaldevice of claim 2, wherein the hub projection extends between the shaftand the liner.
 4. The medical device of claim 1, wherein the shaftincludes a super elastic nickel-titanium alloy.
 5. The medical device ofclaim 1, wherein the shaft includes a linear elastic nickel-titaniumalloy.
 6. The medical device of claim 1, wherein the tip member includesa radiopaque marker.
 7. The medical device of claim 1, wherein the tipmember includes a coil.
 8. The medical device of claim 1, wherein theliner includes two or more layers.
 9. The medical device of claim 1,wherein at least a portion of the liner is movable relative to theshaft.
 10. A medical device, comprising: an elongate shaft having aproximal end and a distal end; wherein the shaft has a plurality ofslots formed therein; a liner disposed within the shaft, the linerhaving a distal region disposed distally of the distal end of the shaft;a hub having a distal portion coupled to the proximal end of the shaftand to a proximal end of the liner; and wherein a gap is defined betweenthe shaft and the liner at a position adjacent to the hub; wherein theproximal end of the shaft and the proximal end of the liner terminate atsubstantially the same axial location.
 11. The medical device of claim10, wherein the hub includes a hub projection that extends into the gap.12. The medical device of claim 10, wherein a tip member is coupled tothe distal region of the liner.
 13. The medical device of claim 12,wherein the tip member includes a radiopaque marker.
 14. The medicaldevice of claim 12, wherein the tip member includes a coil.
 15. Themedical device of claim 10, wherein the liner includes two or morelayers.
 16. The medical device of claim 10, wherein at least a portionof the liner is movable relative to the shaft.
 17. A medical device,comprising: an elongate shaft having a proximal region and a distalslotted region; a liner disposed within the shaft; wherein the liner hasa distal section extending distally of the distal slotted region and aproximal section extending proximally of the distal slotted region; atip member coupled to the distal section of the liner; a hub coupled tothe shaft and to the liner; wherein the hub is coupled to the shaft at afirst attachment region at a distal end of the hub; and wherein the hubis coupled to the liner at a second attachment region at the distal endof the hub radially spaced from the first attachment region so that agap is defined between the shaft and the liner.
 18. The medical deviceof claim 17, wherein the hub includes a hub projection that extends intothe gap.
 19. The medical device of claim 17, wherein the liner includestwo or more layers.
 20. The medical device of claim 17, wherein at leasta portion of the liner is movable relative to the shaft.